Threadripper 2950x, Gigabyte X399 Designare EX BIOS F12, 64GB RAM (4x16GB) Corsair DDR4 Vengeance LPX Black, PC4-25600 (3200), Non-ECC Unbuffered, CAS 16-18-18-36, XMP 2.0, 1.35V
This system has been working perfectly for nearly 2 years. Just recently its refused to switch on, even so much as to trigger the PSU to switch on. When it does this I have to clear the CMOS, then it switches on again. It works for approx a week and then does it again.
I noted that after doing this a few times I had not been re-enabling XMP on my memory, so I did that. The system switches on but fails to post with code F9 'Recovery capsule is not found', then d0 'CPU initialization error', then switches itself off.
It does this 3 times after which it boots normally, (I assume it turns XMP off at this point) but when I check the memory speed its running at 2133. Should be 3200.
I have tested each of my 4 DIMM individually in single channel mode, they all show exactly the same behaviour.
I have reseated the CPU, the socket was perfectly clean even under a magnifying glass.
Is the d0 error message necessarily indicative of a CPU fault?
Has anyone else had a problem with Threadripper suddenly not liking high memory clocks?
I personally am leaning towards the Mobo, but not sure how to go about proving it having no way to swap out CPU or Mobo.
Any thoughts?